Diaphragms for fluid



Feb. 7, 1956 J. w. PRATT DIAPHRAGMS FOR FLUID-FILLED PAD BOXES FiledNOV. 10, 1954 Inventor John WPrafL By his Azzforney W tion.

' DIAPHRAGMS FOR FLUID-FILLED PAD BOXES John William Pratt, Leicester,England, assignor to United Shoe Machinery Corporation, Flemington, N.J., a corporation of New Jersey Application November 10, 1954, SerialNo. 468,115

Claims priority, application Great Britain November 14, 1953 2 Claims.(Cl. 12-38) disclosed in United States Letters Patent No. 1,901,546,

granted March 14, 1933, in the name of George H. Barge, and No.2.657,406, granted November 3, 1953, in the name of Frank C. Choice, inwhich a cemented sole or half sole is pressed against a previouslycemented shoe bottom by means of a pad box comprising a hollow metalreceptacle having clamped about its rim a flexible diaphragm, the padbox being adapted to contain fluid, preferably, water, which permits thediaphragm to conform to the shape of the shoe bottom and offersresistance so that the necessary pressure may be exerted upon the shoeto effect the necessary pressure may be exerted upon the shoe to elfectattachment of the sole to the shoe. Means is usually provided forheating the water to accelerate the drying of the cement.

; Diaphragms made of canvas-reinforced rubber for use with this type ofshoe bottom pressing apparatus are well known and have produced goodresults when operating on mens shoes having reasonably flat bottoms.When, however, shoes to which high heels are afterward to be attachedare being operated upon, rubber blocks suitably shaped to fill in thegap between the shank portion of the shoe bottom and the relatively fiatdiaphragm are sometimes provided. These, however, tend to prevent theconduction of heat from the pad to the shank portion of the shoe bottom,thus preventing acceleration of the drying of the cement in thatportion. There is also a tendency for the canvas'reinforcement tofracture at points where the diaphragm is repeatedly flexed, for examplealong the inside edge of the clamping member which holds the diaphragmto the receptacle.

Diaphragms unreinforced with canvas have been used to apply suitablepressure to the arched shank por- These, however, while beingsufliciently flexible to apply pressure to the shank portion, usuallydistend undesirably around the sole edge and require the use of a maskplate to prevent upward distortion of the marginal portion of the solearound the forepart of the shoe. Moreover, unreinforced diaphragms alsoextend upwardly around the inner edge of the aforesaid clamping memberand thus have a tendency to crack in this locality. Furthermore, whenhigh-heeled shoes are being half-soled, the necessary placing of theforepart portion of the shoe bottom on the pad in such a position thatthe heel of the shoe projects downwardly in front of the pad box allowsthe unreinforced diaphragm frequently to balloon at the forward edge ofthe box. This has a tendency to push off the heel of the shoe.

United States Patent 2,733,462 Patented Feb. 7, 1956 ice One of thevarious objects of the invention is to provide a more durable shoebottom engaging diaphragm for pad boxes which shall be sufficientlyflexible to operate efliciently in the arched shank portion of a shoebottom and yet will not baloon or distend undesirably in the mannerabove described.

With this object in view, the illustrated apparatus is provided with ashoe bottom engaging diaphragm of rubber in which, over the greaterportion of its area, is molded two layers of nylon mesh for the purposeof reinforcement and of reduction of stretchability' and wherein thenylon reinforcement is omitted from the region of the diaphragm whichnormally engages the shank portion of the shoe.

With such an arrangement the portion of the diaphragm having noreinforcement will be more flexible and extensible than the remainder ofthe diaphragm and will swell up against the arched portion of the shoebottom when pressure is applied so that pressure will be eflicientlyapplied to that portion while the remainder of the diaphragm will besufiiciently reinforced to prevent undesirable ballooning without theuse of a mask plate, and the conduction of heat to the shoe will beunimpaired.

The above and other features of the invention will be better understoodfrom the following detailed description when read in connection with theaccompanying drawings and will be pointed out in the appended claims:

In the drawings Fig. l is a View in perspective of the shoe-engagingportion of a pad box;

Fig. 2 is a fragmentary enlarged section through the portion of thediaphragm where the unreinforced portion is located;

Fig. 3 is a fragmentary longitudinal section of the diaphragm shown asconformed to the shank portion of a shoe pressed thereon;

Fig. 4 is a fragmentary. plan view of the diaphragm; and

Fig. 5 is a fragmentary view showing that the margins of the openingsinthe nylon are pinked, the showing of the mesh of the nylon being hereomitted for the sake of clarity.

The illustrated apparatus is a shoe bottom pressing pad which is similarto that disclosed in the Choice patent referred to above. As in thatpatent, the present pad box comprises a hollow metallic receptacle 10open at its top and front and having a diaphragm 12 which extends acrossthe top and down the front portion and which is attached thereto by aclamping member 14 bolted to a flange of the receptacle. The pad isadapted to contain liquid, preferably water. The diaphragm 12 is madefrom a nylon reinforced rubber sheet, the nylon reinforcement consistingof one or more, preferably two, sheets of nylon mesh fabric 16, 17embedded therein. Each sheet of nylon mesh, however, does not extend allover the diaphragm but has an opening 18 therein, as indicated by thedotted line in Fig. 1. The opening in one of the sheets of nylon 16 ispreferably some 4 /2 inches Wide at its rear end and some 3 inches wideat its forward end, the length of the opening from front to rear beingsome 6 inches. The size of the opening in the second sheet 17 of nylonmesh differs from that of the first sheet by approximately half an inchin length and in width so that the diaphragm is generally reinforced bytwo sheets of nylon mesh molded therein but has a portion 20 where thereis no reinforcement and which consists solely of rubber which ispreferably thickened in the portion 20, that is, in the region of theopening 18 in the nylon, the rubber becoming gradually thinner in theregion under the margin of the opening, the purpose being to inj2,733,462 H e creasel the strength of the diaphragm in the unreinforcedPortion...

Preferably also, as indicated in Fig. 5, the margins of the openings inthe nylon sheets 16, 17 are pinked, the notches of the pinking extendingaboutaminchtfrom the edge. of the opening. 18.; andtthe; pointsof;the;pinking in the two sheets being-,preferably-instaggered re.-lation to each other, the. purpose of the: pinkin'g; being to increasethe bond between the nylon sheets atthe margin of the openingl8"with;the rubber inwhiclr they. are embedded.-

The openings in the. nylon register witheach other so that around theedge. of thisunreinforceds portion there is a margin 2220fapproximatelyone-quarten inch inwidth which hasonly; one:thicl ness.-.of; reinforcing. material. This is to minimize any tendency forthe-unreinforced portionofthe diaphragm oflflex sharply at its junctionwith the reinforced. portion. The' forward boundary 24 of theunreinforced.portion liesipreferably some three-quarters of. an inchrearward; of. the. front vertical face 26 of. the. pad:so. that. this;boundaryhis situated near where the. heel end of: awomans shoe having noheel attached (indicated. by dot-and-dash lines in'Figs; 3 and 4)engages thediaphragm and the unreinforced portion extends rearwardlytotthe vicinity of the ball line of the shoe.

By this means, when a full-length soleis being attached to a shoe, thecomparatively flat portion of thei forepart is pressed against thereinforced .region of the-diaphragm while the arched shank portionand'the heel end'portion are pressed against the unreinforced. region.The forward narrower portion of the .unreinforced region. is of suchwidth as to allow the heel-end ofrtheshoe to sinkinto it sufficiently(without causing theadiaphragm to balloon) and to allow the sole to bepressed adequately against the shoe bottom .while the widenrearwardportioncan distend sufliciently when pressure. is applied to pressagainst the upwardly and laterally curved por-- tion of the shank of theshoe.

When a half sole is being. attached to a-shoe which already has a highheel attached to. it, the toe endportion of the shoe is spaced fartherforwardly on the. pad

in such a position that a sufiicient area of the unreinorced. e ion. wable. o. xt nd. pw rdly when, pressure is applied to the shoe and exertadequate pressure to force the heelward margin of the half-sole firmlyagainst the sharply upward sloping portion of the shoe bottom which isimmediately: heelward of the ball line leading to the sharply curvedshank portion. The reinforcement along the: front of thediaphragmprevents ballooning. forwardly. and thus avoids. pressure, on the breastof theoverhanging heel. such as. might tendto force it away fromitsseating onthe-shoe bottom.

With the arrangement above described, the diaphragm issufficiently'flexed in theunreinforcedregion-to operate efficientlyon.the. arched; shank portionofthe shoe bottom while ballooning-.015;undesirable distention or fracture of the diaphragm is prevented by thenylon mesh reinforcement. Since this arrangement eliminates the use ofthe shaped rubber blocks above mentioned, heat will be conductedfrormthe. water in the pad to the shoe bottom as usuaL.

Having thus described my invention,- .what I claim as new anddesire-tosecure by, Letters Patent of the United States is:

1. A pad box. diaphragm comprising. two separate layers of nylon meshembeddedin rubber, each layer having an openingtherein in the regionwhich is to engage theshankportion of a shoe, the opening in onelayerbeingllarger thanthe opening. in the other layer.

2. A pad box diaphragm according. to claim 1 in which the margins of thelayers of nylon about the openings are -pinked..

Refercrwesv Cited-in the file of this patent UNITEDjSTATES PATENTS2,311,325 Anderson Feb. 16', 1943 2,428,814 Russo; Oct. 14, 19472,460,168 Caserta, Jan.25, 1949 2,478;575- Fitch Aug. 9, 1949 FOREIGNPATENTS 629,510 Germany May-4, 1936

